Aussiedistiller, Home Distilling, Moonshine, Home Brew

Is there a thread specific for cap builds can't find much specifics

Doubleuj wrote:

warramungas wrote:That top picture is speccy but it wouldn't need a downcomer pipe in the middle. Just a hole as anything that makes it over the top can go downwards. Its like one of those caps with the downcomer in the middle just on a larger scale.
I built something similar for my 2" column.

You'd still need a downcomer to act as a vapour lock :-B

The internal bit, I'm presuming by the picture there's no slots in the middle and whatever overflows would be the return, would be the riser.

Can someone please explain to me how this plate works? Where is the riser?

See the holes on inside of brown ring. The hole brown bit is the riser. Distance from plate to holes is bath depth. At least I think so :-B would need downcommer shorter than bath depth though..

No, the downcomer is what sets the bath depth...

The whole ring can't be a riser, the riser has to be taller than bath depth.

Is there heaps of small diameter risers inside the donut?

I'm with you zak, I can't follow :think:
If that whole ring doesn't have a bottom and is the "riser" it can't work as a bubble cap, it is then just a side injecting perf plate. It would need to be run the same, plenty of power so the liquid doesn't just run back out the slots at the bottom. If thats the case it would still need a downcomer to set the bath level or it wouldn't have reflux. If you are then just relying on those few slots around the bottom for bubbles you wouldn't have anywhere near as many as a perf plate....

Whilst writing this I had a thought... if there was another ring in the middle of the colomn wall and the slot wall with holes up high it would then become a riser wall and then be bubble cap...mmmm

You might be onto something, I look forward to seeing how it turns out.

Hey Flowerpot,

Any further thoughts on this concept? I am keen to see where you are at.

For the rest of you gents,

Is there a ratio of thoroughfare for want of a better word for vapour path up to downcomer down in each plate. Specifically for a 4" bubble cap plate? Sorry if it has been discussed, I have read so many posts, I just can't seem to find it.

The reason I ask, and to belay any fears of a thread hijacking :)) is that it may help with this concept. It may be that the larger ring of slots or holes may be excessive and flood the ring and oscillate between producing bubbles and not. It would have to be best to be able to produce greater than enough pressure to completely displace the pool of liquid which would mean restricting vapour flow to some degree at the slots / holes.

sorry... post an idea with a krappy confusing picture then get flooded with actual paid work :angry-banghead: hopefully i'll be able to get out to the shed soonish and slap a prototype together that will be a bit more easy to understand.

I'm back :greetings-waveyellow:

I've banged a tryout very roughly together enough to see how it is supposed to work.

Bottom plate: pretty normal downcomer in the middle. The holes around the edge are for rising vapours (should really be as big as possible or even curved slots)


Bubbly bit: pretty much just an inside-out bubble cap


Inside the still they would fit together like this The outside wall of the still forms part of the riser.


Looking from the bottom. It really looks like it needs those holes joined together, looks really restrictive atm.


Assembled looking in from the top


Had tried to make the "bubbly bit" a pretty tight fit in the still tube so it would not need sealing. Will see, may have to solder it in or seal it some other way. Now I think about it, it will need a dab of solder to hold it in place or it will rattle around like crazy.

Nice one, love the creatively :handgestures-thumbupleft:

Looks like it will work so it’s definitely worth a try. My only concern would be that there may not be as much plate area for activity but then again multi caps take up room aswel I guess but in saying that they do have slots all the way around them mmmm :-B I look forward to hearing the results. Keep up the good work mate.

I don't think your downcomer is wide enough and won't allow fast enough draining. This leads to flooding of the plate forcing you to run it slower.

Also might need to flare the top of the downcomer to help stop flooding the downcomer.
As for bottom plate holes they do look quite restrictive.
I would remove all of it except for 4 sections about 5mm long equidistant at 90° between, like really long curved slots.

You will also need a method of directing the condensate to the outside of the module below.
If each plate drops into the centre alot of your reflux will just shortcut back to the boiler.

Thanks guys. Good point about the downcomer i think it needs to be bigger too. i was thinking a simple disc on the bottom of the downcomer would work to distribute the condensate outwards.

going to slap it on my boiler now and see what happens.

it bloody works. :happy-partydance: :happy-partydance: :happy-partydance:

Picks and or video?
I gotta see these things in action :handgestures-thumbupleft:

Yes, video please!!! or pics at least... no. Video!!! :text-lol:

is the copper of the downcomer enough to deal with the sulphates or will you have some of your column in copper?

I think you'll want copper in the vapour path rather than liquid path. Even though some vapour will get close to the downcomers you'll want copper somewhere where all the vapour comes past. The reaction between the copper and sulphides will probably happen in the liquid phase but will happen a lot faster in vapour phase.

Nice one ,maybe your top plate could be held down to the bottom plate with 3-4 stainless spring's,call that Mk 1 for sure.cheers hillzabilly :handgestures-thumbupleft:

Flowerpot wrote:Thanks guys. Good point about the downcomer i think it needs to be bigger too. i was thinking a simple disc on the bottom of the downcomer would work to distribute the condensate outwards.

going to slap it on my boiler now and see what happens.

Or solder a 90"elbow of 1/4 -3/8 inch onto the side of the downcomer cup like this.cheers hillzabilly :handgestures-thumbupleft: